Dual boundary element analysis for a pair of inverted T-type porous barriers having nonlinear pressure drop

Abstract

In the present study, scattering of gravity waves by different wave barrier configurations is analyzed under the assumptions of small amplitude wave theory. The wave past barriers are assumed to follow a nonlinear pressure drop boundary condition . The boundary value problem is solved using iterative Dual Boundary Element Method (DBEM) which facilitates the problem-solving in a single domain. Based on the hydrodynamic characteristics, it is revealed that a pair of inverted T-type porous barrier is effective for wave damping application. Further, a parametric analysis is carried for the inverted T-type barrier to understand the effect of porosity, relative submergence of the barrier, relative spacing between the barriers and relative width of barriers on wave scattering, wave forces and moments. It is observed that increasing the porosity of the inverted T-type twin barrier increases the wave transmission but reduces the wave forces and moments. It is revealed that the relative depth of submergence h 1 / h significantly affects the wave scattering and wave loads on the twin inverted T barrier. Varying the relative spacing between the inverted T-type barrier, S / h from 0 to 1 does not change the wave transmission significantly but changes the wave forces and moments appreciably. It is recommended to increase the value of relative width of the wave barrier, B / h , only if wave transmission need to be reduced considerably for a selected porosity, the relative depth of submergence and relative spacing between the barrier, but at the expense of higher vertical wave force and wave-induced moments. The study results are expected to be useful for optimized design of inverted T-type wave barrier for a wide range of wave conditions.